Does an asymmetric slew rate really matter at all? Presumably, we avoid getting anywhere near the slew rate limit of any signal electronics. I don't think that a difference in slew rate is going to matter in that case. If we are near the slew rate limits, we have other problems as well. Making the slew rates the same is not going to help much. [snip]

-Chris

I like the discussions in Bruno Putzeys' article in Linear Audio Volume 1, "The F-Word". Opinionated but loveable, as used to be said about a TV personality in Los Angeles.

Does an asymmetric slew rate really matter at all? Presumably, we avoid getting anywhere near the slew rate limit of any signal electronics. I don't think that a difference in slew rate is going to matter in that case. If we are near the slew rate limits, we have other problems as well. Making the slew rates the same is not going to help much.

It does, Chris
And you are right, the same illness is reflected on other problems, like intermodulation of signals and their envelopes by phase and amplitude that sounds alien to perceprion of sounds. Especially, when they are high pitch signals, even ten microsecond between channels screws down image localization.

" The Improved Clamond Thermopile: 1879.
The EMF of this pile was no less than 109 Volts, with an internal resistance of 15.5 Ohms. The maximum power output was therefore 192 Watts, at 54 Volts and 3.5 Amps.

This pile was fired by coke. The hot junctions were at C, while the cold junctions D were cooled by sheet iron as in the original design above. What purpose was served by the tortuous path T-O-P taken by the hot gases is unclear, because there seem to have been no hot junctions in the inner sections.
This beast was 98 inches high and 39 inches in diameter...

"A Russian thermo-electric generator based on a kerosene lamp.
This lamp was introduced in 1959, once again to power radios. Presumably there were parts of Russia that Stalin's electrification program had not reached. The output voltage(s) are unknown, but since a picture is known to exist of it powering a valve radio, HT must have been generated somehow, possibly by a vibrator power supply.
(In this context a vibrator is an electromechanical device, similiar to an electric bell, that chops low-voltage DC into crude AC that can be applied to a step-up transformer. They were widely used in car radios before semiconductors arrived)

I have just been informed by Pine Pienaar that he has seen one of these things, and it yielded both 1.5 and 90 Volts, so it could replace a composite dry battery with the same output voltages. Such batteries were once widely used to operate small radios.
Such radios typically used four 7-pin valves and needed a 90V HT supply at around 12mA and a 1.5V filament supply at 125mA or 250mA depending on the valves used.
...